题目内容
（请给出正确答案）
Laser-dopple radar is especially valuable in space missions because it ______ .
A．is one thousand times more precise than microwave radar
B．provides precise measures of the velocity of space vehicles
C．is a new system of radar
D．can measure the movement of a spaceship less accurately than a microwave radar
如果结果不匹配，请 联系老师 获取答案
更多“Laser-dopple radar is especial…”相关的问题
Which of the following statements is NOT true according to the passage ______.
A．accuracy in speed measurement is essential to spaceships
B．the speeds of space vehicles will vary greatly
C．inaccuracies in measurement could cause accidents in space missions
D．a bump could affect the preciseness of the laser-dopple radar
Laser-dopple radar is especially valuable in space missions because it ______.
A．is one thousand times more precise than microwave radar
B．provides precise measures of the velocity of space vehicles
C．is a new system of radar
D．can measure the movement of a spaceship less accurately than a microwave radar
Implied but not stated ______ .
A．Laser-dopple radar is more accurate than microwave radar
B．Microwave radar may not ensure absolute precision in measuring varying speeds
C．The light-beam radar can measure only slow speeds with accuracy
D．Microwave radar operates at a higher frequency than laser-dopple radar
Implied but not stated ______.
A．Laser-dopple radar is more accurate than microwave radar
B．Microwave radar may not ensure absolute precision in measuring varying speeds
C．The light-beam radar can measure only slow speeds with accuracy
D．Microwave radar operates at a higher frequency than laser-dopple radar
Which of the following statements is NOT true according to the passage ______ .
A．accuracy in speed measurement is essential to spaceships
B．the speeds of space vehicles will vary greatly
C．inaccuracies in measurement could cause accidents in space missions
D．a bump could affect the preciseness of the laser-dopple radar
The model has shown that this radar system, known as laser-dopple radar, can measure with absolute precision speeds varying from spaceship orbital injection(进入) velocities(速度) of five miles per second down to virtual stops-speeds of less than one-thousandth of an inch per second. According to the scientists who are developing this system, such fine measures of velocity are of prime importance in space missions. In a rendezvous(对接) between two spaceships, or in a landing approach by a vehicle onto an orbiting space station, a bump could rip open a ship's skin, or a nudge could knock the station out of its orbit.
The light-beam radar, which operates at a frequency of trillions of cycles(百万兆) per second, could easily detect and measure the movement of a vehicle edging up to a satellite space station. A control system using so precise a signal as this would allow a huge vehicle to dock at a space station as lightly as a feather.
Laser-dopple radar ______.
A．measures the movement of a spaceship by means of light beam
B．makes use of microwaves
C．makes use of sound waves
D．both A and B
听力原文：M: May I see your license？
W: But officer, did I do something wrong？
M: Did you see the speed limit sign. It says thirty five miles an hour here.
W: But my speed meter reads only thirty miles.
M: Then why did my radar show you're going forty five.
What is the speed limit in that area？
A．30 miles.
B．35 miles.
C．40 miles.
D．45 miles.
听力原文：M: I'm sorry I'm late, Cindy.
W: That's all tight, Joe. My house isn't that easy to find. But you know, you wouldn't have gotten lost if you had a "smart" car.
M: A smart car？ What's that？
W: I just read a magazine article about some new technology that can make a car smart. One device is a computerized map display and a synthesized voice, you must enter the address where you want to go, and the voice tells you how to get there, street by street.
M: Hey, that's just like my brother. He never gets lost, and he's always telling me the best route. So what else will smart cars be able to do？
W: Well, the article said that they'll be equipped with radar warning systems that will warn drivers if they're getting too close to other cars with an alarm signal, and they'll even put on the brakes if the drivers don't.
M: Tell me, Cindy, will these cars be smart enough to fill themselves up with gas？
W: Not that I know of. Why do you ask？
M: Well, I'm late not because I got lost—I'm late because I ran out of gas on the way over here.
(20)
A．From a newspaper advertisement.
B．From a magazine article.
C．From a television program.
D．From an automobile dealer.
听力原文：M: I'm sorry I'm late, Cindy.
W: That's all right, Joe. My house isn't that easy to find. But you know, you wouldn't have gotten lost if you had a "smart" car.
M: A smart car？ What's Bat？
W: I just read a magazine article about some new technology that can make a car smart. One device is a computerized map display and a synthesized voice, you must enter the address where you want to go, and the voice tells you how to get there, street by street.
M: Hey, that's just like my brother. He never gets lost, and he's always telling me the best route. So what else will smart cars be able to do？
W: Well, the article said that they'll be equipped with radar warning systems that will warn drivers if they're getting too close to other cars with an alarm signal, and they'll even put on the brakes if the drivers don't.
M: Tell me, Cindy, will these cars be smart enough to fill themselves up with gas？
W: Not that I know of. Why do you ask？
M: Well, I'm late not because I got lost—I'm late because I ran out of gas on the way over here.
(23)
A．$ 5
B．$ 15
C．$ 30
D．$ 250
听力原文：M: I'm sorry I'm late.Rose.
W: That's all right,Vic.My house isn't that easy to find.Many of my friends have trouble finding the way when they come for the first time.But you know,you wouldn't have gotten lost if you had a"smart"car.
M: A smart car？I have never heard of that before.What's a smart car？
W: I just read a magazine article about some new technology that can make a car smart.One device is a computerized map display and a synthesized voice,you must enter the address where you want to go,and the voice tells you how to get there,street by street.
M: Hey,that's just like my brother.He never gets lost,and he's always telling me the best route.So what else will a smart car be able to do？
W: Well,the article said that they will be equipped with radar warning systems that will warn drivers if they're getting too close to other cars with an alarm signal,and they will even put on the brakes if the drivers don't.
M: Tell me,Rose,will these cars be smart enough to fill themselves up with gas？
W: Not that I know of.Why do you ask？
M: Well,I'm not late because I got lost--I'm late because I ran out of gas on the way over here.
What do we learn about a"smart"car according to the woman？
A．It uses new technology.
B．It is installed with a robot.
C．It is as clever as human.
D．It can talk with people.
